Rotor rub-impact acoustic emission recognition method based on modal waves and gauss hybrid models

Abstract

The invention discloses a rotor rub-impact acoustic emission recognition method based on modal waves and gauss hybrid models. The method comprises the following steps: adopting a rub-impact acoustic emission tester to acquire acoustic emission signals and perform short-time framing on the acoustic emission signals; respectively extracting a cepstrum coefficient for each short-time frame, calculating the fractal dimension, and combining the cepstrum coefficient and the fractal dimension into hybrid characteristic parameters for the recognition of the rub-impact acoustic emission signals; determining the variety of the modal waves in the rub-impact acoustic emission signals; respectively establishing a corresponding gauss hybrid model for each type of the modal waves, and independently usingthe gauss hybrid model to train each modal wave in the rub-impact acoustic emission signals; merging the output likelihood ratio of various modal wave models according to certain weight proportion toobtain the total likelihood ratio during recognition; and finally judging the total likelihood ratio. The rotor rub-impact acoustic emission recognition method based on the modal waves and the gausshybrid models can accurately recognize the rub-impact acoustic emission signals, and not only can be applied to the recognition of unexpected acoustic emission signals, but also can be applied to therecognition of continuous acoustic emission signals.

Description

technical field [0001] The invention relates to a rotor rubbing acoustic emission identification method based on a modal wave and a Gaussian mixture model, and belongs to the technical field of acoustic emission signal identification methods. Background technique [0002] Dynamic and static rubbing is an important research topic for large rotating machinery. The conventional vibration detection method is not ideal for judging the rubbing effect, especially when the early characteristics of rubbing are weak, the vibration detection method has great difficulties. Acoustic emission (Acoustic Emission, AE) provides a new way for rubbing detection and recognition with its unique advantages. Compared with the vibration signal, the AE signal has a wide frequency response range, a large amount of information, and a high signal-to-noise ratio. Especially when the early fault characteristics are weak, it can make up for the defect that the vibration signal is not sensitive to weak rub...

AI Technical Summary

Problems solved by technology

However, due to the prominent noise interference problems faced by AE, especially the relatively harsh working environment of rotating machinery and the multi-source strong noise generated by the equipment itself during operation, coupled with the attenuation and distortion of AE signals in the process of structure propagation, interest in The identification of the rubbing AE signal becomes more difficult, and the current research on the identification method of the rotor rubbing AE is not deep enough, so the rubbing fault diagnosis based on AE technology has not yet played its due role

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